1. Technical Field of the Invention
The present invention relates to performance monitoring of Location-based Service (LBS) in a mobile telecommunications network having nodes providing both positioning information and application information relating to the location of a subscriber accessing over either circuit-switched or packet-switched network. In particular, and not by way of limitation, the present invention is directed to a method, a device and a system for monitoring of LBS for a telecommunications network, such as General Packet Radio Service (GPRS) or CDMA2000 networks.
2. Description of Related Art
LBS is a value-added service of mobile telecommunications networks, such as the GPRS network of the Third Generation Partnership Project (3GPP). LBS systems make use of the Positioning service of the mobile network of the requested subscriber to obtain an estimate of the current geographical location of his/her mobile terminal. The accuracy of the positioning depends on the deployed method in the range from few meters assisted by the Global Positioning System (GPS) to few kilometers in case of cell based methods. Based on the obtained position, the LBS system performs a lookup in a spatial-organized geographic database to locate the specified objects, maps, etc in the neighborhood of the given position and produces the desired output.
Eventually, LBSs are a set of applications running on an LBS server. LBS systems typically support the functions of locating the nearest point-of-interest (POI), e.g. a petrol station, navigating to the selected point-of-interest, and running fleet management and tracking. Each function may produce rich-text, image or animated-image output for the terminal, which renders the information, after optional preprocessing, on its display.
Market success of LBS largely depends on its performance and on the reliability of the provided information. Quick response and up-to-date, valid information are inevitable prerequisites of high penetration. Therefore, continuous performance monitoring in live operation is important. Furthermore, performance monitoring shall provide helpful information for the operator to identify performance bottlenecks of the operating system.
Until now, the accuracy and the performance of the Positioning subsystem were in the major focus and the overall performance of the LBS was not an issue. For example, Spirent's Position Location Test System (PLTS) offers automated active measurement-based accuracy and performance tests for handsets and networks for CDMA2000 systems, as it is described in Spirent Communications, Positioning Location Test System, http://www.spirentcom.com/documents/119.PDF
Besides active measurements, each node in the mobile system maintains its own operation logs and a set of counters related to the provided service. These logs and counters are associated with a certain procedure or events performed in the node, which is useful but inadequate for describing the overall performance. For example, the counters “number of successful requests” and “the number of total requests” are maintained at the Gateway Mobile Location Center (GMLC) node, however they cannot be related to individual subscriber requests.
A more detailed view can be established with passive measurements. A monitoring tool described in U.S. Pat. No. 6,807,156 for example, is able to monitor and analyze end-to-end performance and inspect traffic characteristics of packet traffic recorded at one of the standard 3GPP packet interfaces. The method provides means to investigate performance of LBS-related protocols such as Wireless Application Protocol (WAP), Hypertext Transfer Protocol (HTTP) or Transmission Control Protocol (TCP).
The operator wants to provide an attractive service with good end-user experience; therefore the operator is definitely interested in monitoring the performance of the service.
The existing solutions, described above, are either focusing on the performance of a certain subsystem, or considering the overall performance at aggregate level.
The limitation of the counter based approach is that it only provides aggregate statistics of a certain event or procedure. Positioning events can be related neither to a given subscriber or set of subscribers, nor to a specific geographic region.
The drawback of log-based approach is that in multi-vendor environment the collection and processing of the information is not standardized. Moreover, the vendor of the GMLC, LBS and WAP or HTTP gateway nodes may be different, hence the correlation of logs to find a specific event may lead to a cumbersome task.
The disadvantage of active measurements is that it can be performed from only a limited set of terminals in order to keep the induced load low, and only from a limited set of geographic areas. There is also a need to take care of moving the terminals.
The limitation of the single monitoring-point passive measurements is that it provides a partial insight into to LBS system performance, i.e. either only the positioning part or the overall LBS system excluding the details of the positioning, can be considered. In the first case, there is no background information on the requested LBS action, i.e. who and why did the positioning request. In the second case, there is no direct information over the positioning part, because the obtained position is used to index the database and the response includes post-processed information, e.g. a map in image format. Hence the LBS request can be bound neither to a user nor to a geographic location, and it cannot be determined whether positioning or the database performance is the bottleneck.